In a traditional x-ray tube, the source of electrons is which component?

In a traditional x-ray tube, the cathode filament is responsible for generating the source of electrons. When an electric current passes through the filament, it heats up and undergoes a process called thermionic emission, whereby electrons are emitted from the filament. These emitted electrons are then accelerated toward the anode by a high voltage applied across the tube.

The other components mentioned have different roles. The anode is where the electrons strike to produce x-rays, acting as the target. Xenon gas is sometimes used in specific imaging modalities but is not a standard component in a traditional x-ray tube design. A lead shield serves to protect the surrounding environment from unwanted radiation exposure and does not play a role in electron production. Understanding the role of each component in the x-ray tube helps clarify the function of the cathode filament as the electron source.